Your playthrough doesn't have to end when the Vampire Gods are gone.
Arkane is known for its games that are both expansive and freeing to let you go at situations your own way. Redfall may not hit the way Dishonored or Prey did, but it still has plenty of content for a playthrough and beyond. If you complete the game, you will still have time to sink your fangs into.
Redfall breaks its open world into various sections. Each location has plenty of things to do, from side quests

to lore to read. Whether you like digesting the world-building or want to tick off boxes to complete a goal, you will have something to enjoy when you finish the main story. No matter what you do, make sure you do it before beating the final mission, as it will kick you into the main menu and start your campaign over.